Conventionally known is a foldable child seat (see Patent Literature 1, for example).
The child seat includes a seat body having a seat surface portion and a back support portion, and a belt. The seat surface portion and the back support portion are joined to each other at a joint portion, and the seat body is foldable at the joint portion. Accordingly, in a non-use state, by folding the seat body, it is unnecessary to provide a large space for storing the child seat.